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Related papers: Imaging Spectroscopy of a White-Light Solar Flare

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A popular scenario for electron acceleration in solar flares is transit-time damping of low-frequency MHD waves excited by reconnection and its outflows. The scenario requires several processes in sequence to yield energetic electrons of…

Astrophysics · Physics 2015-06-24 Arnold O. Benz , Pascal Saint-Hilaire

The Neupert effect refers to the strong correlation between the soft X-ray (SXR) light curve and the time-integrated hard X-rays (HXR) or microwave flux, which is frequently observed in solar flares. In this article, we therefore utilized…

Solar and Stellar Astrophysics · Physics 2024-04-04 Dong Li , Hanyang Dong , Wei Chen , Yang Su , Yu Huang , Zongjun Ning

In this work, we studied X-ray source SRGe~J021932.4$-$040154 (SRGe J021932), which we associated with a single X-ray active star of spectral class G2V-G4V and the rotational period $\rm P_{rot} < 9.3$ days. Additional analysis of TESS…

High Energy Astrophysical Phenomena · Physics 2024-12-13 Andrey Mukhin , Roman Krivonos , Ilfan Bikmaev , Mark Gorbachev , Irek Khamitov , Sergey Sazonov , Marat Gilfanov , Rashid Sunyaev

With machine learning entering into the awareness of the heliophysics community, solar flare prediction has become a topic of increased interest. Although machine learning models have advanced with each successive publication, the input…

Solar and Stellar Astrophysics · Physics 2020-03-11 Brandon Panos , Lucia Kleint

We present unique NUV observations of a well-observed X-class flare from NOAA 12087 obtained at Ond\v{r}ejov Observatory. The flare shows a strong white-light continuum but no detectable emission in the higher Balmer and Lyman lines. RHESSI…

Solar and Stellar Astrophysics · Physics 2017-03-08 Ondřej Procházka , Ryan O. Milligan , Joel C. Allred , Adam F. Kowalski , Pavel Kotrč , Mihalis Mathioudakis

The Helioseismic Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO) records line-of-sight Dopplergram images of convective flows on the surface. These images are used to obtain the multi-scale convective spectrum. We design…

Solar and Stellar Astrophysics · Physics 2021-08-09 Samarth G Kashyap , Shravan M Hanasoge

We report the detection of emission from a non-thermal electron distribution in a small solar microflare (GOES class A5.7) observed by the Nuclear Spectroscopic Telescope Array (NuSTAR), with supporting observation by the Reuven Ramaty High…

X-ray and EUV observations are an important diagnostic of various plasma parameters of the solar atmosphere during solar flares. Soft X-ray and EUV observations often show coronal sources near the top of flaring loops, while hard X-ray…

Solar and Stellar Astrophysics · Physics 2015-06-11 Marina Battaglia , Eduard P. Kontar

We present a concept for a machine-learning classification of hard X-ray (HXR) emissions from solar flares observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI), identifying flares that are either occulted by the…

Solar and Stellar Astrophysics · Physics 2021-02-24 Shin-nosuke Ishikawa , Hideaki Matsumura , Yasunobu Uchiyama , Lindsay Glesener

Regularized imaging spectroscopy was introduced for the construction of electron flux images at different energies from count visibilities recorded by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). In this work we seek…

Solar and Stellar Astrophysics · Physics 2023-11-14 Anna Volpara , Paolo Massa , Sam Krucker , A Gordon Emslie , Michele Piana , Anna Maria Massone

Context: Flare kernels brighten simultaneously in all SDO/AIA channels making it difficult to determine their temperature structure. IRIS is able to spectrally resolve Fe xxi emission from cold chromospheric brightenings, so can be used to…

Solar and Stellar Astrophysics · Physics 2016-02-17 D. Li , D. E. Innes , Z. J. Ning

On 2011 September 6, we observed an X2.1-class flare in continuum and H$\alpha$ with a frame rate of about 30~Hz. After processing images of the event by using a speckle-masking image reconstruction, we identified white-light (WL) flare…

Solar and Stellar Astrophysics · Physics 2016-12-14 Tomoko Kawate , Takako T. Ishii , Yoshikazu Nakatani , Kiyoshi Ichimoto , Ayumi Asai , Satoshi Morita , Satoshi Masuda

We present a case study of an M4-class flare on 28 March 2022, near Solar Orbiter's first science perihelion (0.33 AU). Solar Orbiter was 83.5{\deg} west of the Sun-Earth line, making the event appear near the eastern limb, while…

Sympathetic solar flares are eruptions that occur nearby in space and time, driven by an apparent interaction between the active regions in which they are triggered. Their statistical existence on the Sun has yet to be firmly established.…

Solar and Stellar Astrophysics · Physics 2025-02-05 Louis-Simon Guité , Antoine Strugarek , Paul Charbonneau

Deriving a well-constrained differential emission measure (DEM) distribution for solar flares has historically been difficult, primarily because no single instrument is sensitive to the full range of coronal temperatures observed in flares,…

Solar and Stellar Astrophysics · Physics 2014-06-25 Amir Caspi , James M. McTiernan , Harry P. Warren

Fiber bursts are a type of fine structure that is often superposed on type IV radio continuum emission during solar flares. Although studied for many decades, its physical exciter, emission mechanism, and association with the flare energy…

Solar and Stellar Astrophysics · Physics 2017-10-25 Zhitao Wang , Bin Chen , Dale E. Gary

We analyse the observational characteristics for a set of Long Duration Events (LDE) using Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). Excellent energy resolution (1 keV) of HXR images reconstructed with RHESSI allowed us…

Solar and Stellar Astrophysics · Physics 2015-03-19 Tomasz Mrozek , Zbigniew Koltun , Sylwester Kolomanski , Urszula Bak-Steslicka

Increase in the Balmer continuum radiation during solar flares was predicted by various authors but never firmly confirmed observationally using ground-based slit spectrographs. Here we describe a new post-focal instrument - Image Selector…

Solar and Stellar Astrophysics · Physics 2016-02-02 P. Kotrč , O. Procházka , P. Heinzel

White-light flares are the flares with emissions visible in the optical continuum. They are thought to be rare and pose the most stringent requirements in energy transport and heating in the lower atmosphere. Here we present a nearly…

Solar and Stellar Astrophysics · Physics 2017-12-21 Q. Hao , K. Yang , X. Cheng , Y. Guo , C. Fang , M. D. Ding , P. F. Chen , Z. Li

Recent progress in the diagnosis of flare fast particles is critically discussed with the main emphasis on high resolution Hard X-Ray (HXR) data from RHESSI and coordinated data from other instruments. Spectacular new photon data findings…

Astrophysics · Physics 2009-11-11 John C. Brown , Eduard P. Kontar